Mixtures of alcohols as tubing fluids for non-boilable catgut



. 'MIXTURES F ALcoHoLs ASTUBING FLUIDS or: NQN-BOILABLE CATGUT Reginald Rye, N. assignor to Davis Geek, Inc., Danbury, Conn., a corporation of New York 1 No Drawing. Application septemberl t, 1953, r I

S n NQ- 0 1 i 3 Claims. (Cl. 206-63.3)

' This invention relates to surgical sutures'of theproteinaceous type and more particularly to the packaging, preservation and conditioning of non-boilable'surgical sutures. Still more particularly this invention relates to a'method of improvingthe'strength of tubed, non-boil able catgut'sutures while reducing swelling and to. the composition of the liquid in which non-boilable catgut sutures are customarily packaged or tubed.

Strength, flexibility, softness and siz'e' of proteinaceous surgical sutures areimportant physical ,characteristics upon which the" surgeon depends for easyand rapid manipulation during an operation and the tying of tight, secure knots. Unfortunately, -;these characteristics, normal to gut in the naturalstatgafe substantially lost or destroyed at onestage in the preparation of sutures due to thenecessity for thoroughlydrying'or dehydrating the suture before it can be heat sterilized. This is for the reason that thefpresenc of Water atsterilization temperatures rapidlyzreducesgthe strength o f the suture,

- causes it to swell, and may even convert it completely into an j incoherent, jelly-like mass; As the result of drying and after sterilization, the suture, which has shrunk in size, is hard, stiff and brittle and is in no condition to be used. This is true even when sterilization is carried out 'in the presence of a non-aqueous inert liquid hydrocarbon such as toluol, xylene or the like, as is sometimes done.

.Topreserve the sterility of sterile sutures it is customary to package them individually in sealed glass tube during removal. A disadvantage accompanying the I use of such sutures is that they must be soaked in water or other conditioning solution under aseptic conditions to soften and fiexibilize them before they can be used. Non-boilable sutures, however, are softened and flexi- .bilized by the liquid in. the tube and are available for use substantially immediately upon removal. They cannot be boiled, however, or subjected to sterilizing temperatures because of the damaging effect of the tubing UnitedStates Patent; 0

tubes together with a quantity of a liquid known in the art as tubing fluid. This may be a fluid inert to the suture such as the liquid in whichthe suture was sterilized, in which event the tube with the suture and the liquid inside is labeled boilable; or it may be a different fluid over boilable sutures for the reason thatthey can be used immediately, their use has been hampered by the inability of the known tubing fluids toprovide a suture having optimum strength, flexibility and softness. The exact mechanism by which the fluid or solution strengthens,

softens andflexibilizes thegut is not known. The protein of which gut is composed isexceedingly complex and highly reactive and its characteristics are variously changed and modified depending upon the materials and conditions to which it is subjected.

Water alone, for instance, exerts a powerful effect on gut. Under controlled conditions as to temperatures and time water is anexcellent softener and flexibilizer for gut sutures but, if allowed to remain in contactwith the suture for any extended period the gut swells and continues to swell until the s'uture'is substantially devoid of tensile strength. Absolute ethyl alcohol will soften and flexibil ize gut but only to alimited degree which is not generally satisfactory. 'Ethyl' alcohol containing from 0.5% to 10% of water is commonly used as a tubing fluid, and

.other alcohols,'namely methyl, propyl and isopropyl,

both anhydrous and admixed with varying percentages of water, have been used. Methyl alcohol is ordinarily too irritating to tissue so that its use has neverbeen particularly popular. QPropyl and isopropyl alcohols, both anhydrousand admixed with water, have been used to a lim: ited extent because. they result in substantially less swell ing offthe gut than isjpossible with mixtures of ethyl alcohol and water, but here again toxicity or irritation to tissue with which it comes in contact in a wound has prevented their general adoption. An ethyl alcohol-water solution containing 20% isopropanol and 4% water has heretofore been used as a tubing fluid, but little or no advantage has been apparent'from the. use of this mixture over and above the use of the usual 95% ethyl alcohol-' watertubing fluid. For instance, it is stated in Patent No.

2,524,772 of October 10,. 1950, to Davis, that gut sutures tubes in a fluid containing isopropanol and, 10% water swell only about 50% as much as they do in the g 20% isopropanol, 76% ethanol, 4% water mixture described above. The patent also states that on decreasing the percentage of isopropanol in the 10% water solution to 65% isopropanol and 35% water the advantages of the isopropanolwater mixture over the 20% isopropanol, 76% ethanol and 4% water mixture disappear.

I have found that the advantage in the reduction of suture swelling derived through the use of propyl or isopropyl alcohols alone or in admixture with low concentrations of Water may be substantially retained by the use of only about 65% propyl or isopropyl alcohol and 10% water in admixture with about 25% of an alcohol selectedfrom the group consisting of methanohethanol and tertiary butanol. I have-found that minimum swelling is obtained in the use of the above mixture when terstantially less than one-half as shown in the following table.

- Table Size 000 7 Size Size 0 Size 1 After 31 days at I After 31 days at After 31 days at After 37 days at Solution room temp. Equjlm room temp. Equmh room temp. Equilib. room temp. Equflm Reached, Regched, Reached, V Redached, Percent ays Percent ays Percent Kays Percent ays Swell. Flex. Swen Flex. Swen Flex. Swen. Flex.

65% isoprop. alc.-nnhyd r v 25% text-butyl. alc.-anhyd. 2. 64 8.1 11 4. 64 10. 5 7 7. 51 13. 4 r 1 7. 0 12. 8 8 distilled water I 65% isoprop. ale-anhyd 25% ethyl. alc.-an.hyd 2.91 v 8.0 V 7 6. '10. 1 1 7 6.11 11. 9 ,1 l 8. 11 11.6 8 10% dlslgilled water con 0 f 95% ethyl am MHZ 7.58 6.9 11 12. 77 7. 2 Y 7 is. s 12. 5 v 1 15. a4 10. 0 s

The results set forth in the table were obtained by the following procedure: 5

Thirty strands each of sizes 1, 0, 00 and 000 of plain catgut 3 /2 inches long were gauged for diameter over .a portion mid-way of their lengths and thegauged area marked with two India ink spots. The smallest diameter Within the area marked was recorded for each strand. Each strand was then put in a 12 mm. tube and oven dried and sterilized. After sterilization the tubes were placed in a desiccator over calcium chloride until the diameters of the strands became constant. At this time. 12 tubes of each size were filled with one of the two test solutions and 12 tubes of each size were filled with the other of the two test solutions. The remaining'6 .tubes of each size were filled with the control solution and all the tubes were corked with cork stoppers. The strands were then gauged at periodic intervals according to U. S. P. XIV procedures and the average percent swelling determined for each size in each of the two test solutions and in the control solution as shown in the table. The average percent flexibility of the strands as indicated in'the table was determined at the end of theexperiment.

In' addition to the reduction in swelling of the sutures tubed in the solutions of the composition of the present invention it will be seen that'this decrease in swelling is accomplished without substantialdecrease in flexibility. The quantity of ethyl or tertiary butyl alcohol used also lowers the overall toxicity of the. solution. The tubing fluids of the present invention give equally improved results when used for tubing chromic or chrome-tanned catgut sutures, and in fact may be used to tube all types of non-boilable catgut sutures with or without needles attached, and may contain a small percentage, say .025,

. of phenyl-mercuric benzoate or other appropriate antiseptic if desired.

I claim:

1. As an article. of manufacture, a 'sealed container having thereinin combination a proteinaceous suture and a small quantity of a tubing fluid comprising 65% of a propyl alcohol,'10%. water and 25% of tertiary butyl alcohol.

2. As an article of manufacture, a sealed container having therein ,in combination aproteinaceous suture and a tubing fiuid'comprising isopropyl alcohol, 10% water and 25% tertiary butyl alcohol. 3. As an article of manufacture, a sealed container having therein in combination a proteinaceous suture and a tubing fluid comprising 65% normal propyl alcohol, 10% water and 25 tertiary butyl alcohol.

References Cited in the file of this patent UNITED STATES PATENTS Davis Oct. 10, 1950 Powers Nov. 16, 1954 

1. AS AN ARTICLE OF MANUFACTURE, A SEALED CONTAINER HAVING THEREIN IN COMBINATION A PROTEINACEOUS SUTURE AND A SMALL QUANTITY OF A TUBING FLUID COMPRISING 65% OF A PROPYL ALCOHOL, 10% WATER AND 25% OF TERTIARY BUTYL ALCOHOL. 